Inlet and outlet elements for piston engines



A. J. BUCHI April 11, 1961 INLET AND OUTLET ELEMENTS FOR FISTON ENGINES Filed May 19, 1959 5 Sheets-Sheet 1 April 11, 1961 A. J. Bucm 2,979,046

INLET AND OUTLET ELEMENTS FOR PISTON ENGINES Filed May 19, 1959 5 Sheets-Sheet 2 A. J. BUC Hl INLET AND OUTLET ELEMENTS FOR PISTON ENGINES Filed May 19, 1959 3 Sheets-Sheet ,5

Zh Vae/175k Win64 Bach vill INLET AND OUTLET ELEMENTS FOR PISTON ENGINES Alfred I. Buchi, Archstrasse 2, Winterthur, Switzerland; Hermann Walder, executor of said Alfred J. Buch, deceased Filed May 19, 1959, Ser. No. 814,291

8 Claims. (Cl. 12S-79) The apertures can be spherically triangular in a semispherical dome head, the basis of the apertures being near the maximum diameter of the dome head and the height of the apertures measured axially being about of the base distance of the apertures. K

The bell-shaped valve has a smooth inner surface whereby the transitions to said dome wall portions between said apertures is also smooth and without any recess.

The outer valve body including its tubular shaft is manufactured of one solid piece and does not consist of separable pieces which lead to dierent heat extension and forms eddies for ow losses and would increase the weight ofthe outer valve.

The inner valve is closed by means of torsion spring and said outer inlet valve can be closed by meansbf a spiral spring.

The internal combustion engine can comprise a cylinder head, an outer and an inner valve in said cylinder head, said inner valve being guided with said outer valve, said outer valve having at its inner end a hollow bellshaped portion surrounding said outer valve having at shaped portion surrounding the inner valve situated in the h bell-shaped portion of the outer valve. The outer valve is seated by its bell-shaped portion in the'cylinder head and the inner valve has a valve shaft while the outer valve has a tubular shaft with which the shaft of the inner valve is guided.

The tubular shaft'is connected with an inner hollow semi-spherical shaped portion to the inner bell-shaped portion of the outer valve, which comprises its valve seating arrangement. The semi-spherical-shaped portion has through flow apertures for the pressure medium controlled by the inner valve.

The bell-shaped hollow portion of the outer valve seating arrangement is widened from its inner smallest diameter steadily in outward direction to a maximal inner diameter equal to the inner diameter of the semi-spherical hollow portion to obtain a maximum of through flow area of the apertures in it for the pressure medium and nevertheless to obtain a minimum of length and weight of the two valves. portions of the dome head and each of the wall portions can be situated substantially in an axial plane; the apertures are separated by Wall portions of the dome head 'Ihe apertures are separated by wall .and each of said wall portions can be situated axially or radially to the valve axis. Narrow webs are made up of said semi-spherical transition part. The throughow apertures between the inner hollowpartof the outer valve and its tubular shaft, said inner hollow part of the outer valve being upto its outer tubular shaft, free from'any structure built in such as ribs, hubs, etc., restrictingthe through liow area of the gases which would increase the heating ofthe hollow outer valve body and its weight; not more than three narrow webs made up of said semi-spherical transition part, defining said through flow apertures between the inner hollow part of the outer valve and its tubular shaft can be provided. Y

The wall portions can be arcuate as viewed in the direction of the valve axis. Their dimension in the circumference can be made greater than its radial thickness so as to increase the elasticity of its wall portions in its radial and diaxial direction so as to better withstand stressing substantially in the direction of the valve axis and to transmit the valve operating forces without undue stressing from the hollow valve stem via the arcuate wall portion to the hollow outer and wider valve body itself.

The outer surface of the dome head at the wall portions between the apertures is flared into the outside surfaces of the tubular extension Athereby to increase the mechanical L strength of said wall portions where they join the extension.' e

its inner end a hollow bell-shaped portion surrounding said inner valve being situated in said rbell-shaped portion of said outer valve, said outer valve being seated by its bell-shapedportion in said cylinder head, a valve shaft for said inner valve, a tubular v-alve shaft for said outer valve to guide the shaft of the inner valve. The tubular shaft is connected with a hollow, outer semispherical shaped portion to the inner bell-shaped por.- tion of the outer valve comprising its valve seating arrangement. The semi-spherical shaped portion has through ow apertures for the gas controlled by' said inner valve. The' bell-shaped hollow portion of the outer valve arrangement is from its inner smallest diameter steadily widened in outward direction to the maximal inner diameter equal'to the inner diameter of the lsemispherical lhollow portion to obtain a maximum of through llow area of the apertures for the pressure medium and a minimum of lengths and weight of the two valves.

ln the construction involved the outer and inner valves are interchangeable and can constitute outlet and inlet valves as may b e deemed desirable.

The outer hollow inlet valve comprises an inner outlet or exhaust mushroomv valve received within the outer inlet valve and which s'eats against the bell-shaped portion of the inlet valve.A The latter seats against'a cylinder head opening'. Each valve being independently reciprocated for opening and closing. The hollow inlet valve has a 'semi-spherical-shaped'dome, coaxial with the axis of the 60: the passages in the outer inlet valve through which passes the gases vcontrolled by said inner outlet valve.

The semi-spherical inlet valve head can have not more than three apertures of approximately isosceles spherical triangles.`

Theapertures can be separated by wall portions of the dome head which extend at least partly at an oblique angle to' the valve axis so that the hollow body of the outer valve will at least partly rotate round the cylinder axis when the webs of the dome head expand due to the heating through the thereto passing exhaust gases, so

that the jacket 1a of the outer valve 1 and the walls 1b `and 1e between the apertures 1p will not be ytoo much Patented Apr. 11, 1961,

:attractie 3 submitted'to stressesresulting'froin'thc'elongation of the walls 1b and 1e.

The above enumerates some of the objects to be accomplished by the present invention and the following detailed description will illustrate further objects when considered with with'the drawingsliri'which:

Figure l is a section throughV the" axis of the cylinder head taken on section line I-I of Figure 2 illustrating an example of a general a'rrang'ernenty of the telescope inlet and outlet valvesl of an internal combustion engine.

Figure la shows a part of the same axial section as Figure l of an alternate design for the closing means.

Figure 2 is a section along the line IIx-II of Figure l. Figure 3 showsV a section through the valve axis of another'construction-of the s erniephericals'haped head of the outer valve fromthat showii in Figure 2.

Figure 4 is a plan View' of the bells'haped head' of the outer valve shown in Figure 3; ,Y

Figure l illustrates an' assembly of an exampleV of embodiment according to the invention. Thetel'escope valve elements are shown assembled in the cylinder head of an internal combustion engine'. The inlet valve 1 is placed outside the outlet v`alv`e2 andV the outlet valve 2 inside the inlet valve 1. 3 is the admission duct for the charge and 4 the outlet duct for' the exhaust gas. The valve closing means for the two valves are also shown. These devices consist of the spiral springs 7 and 8 and the spring plates ando. The latter are rigidly connected with the corresponding valve elements. The plate Svwith the outlet valve by means of the bolt 16 and plate 17 and the plate 6 with the inlet valve 1 by means of the threaded hub 18 vthreaded upon the upper end 19 of tubular shaft 1d. o ,l y

The spring 8 rests on cylinder head 9 while spring 7 rests on plate 21 supported on pins 20.

, As can be clearly seen `from Figure l the outer valve 1 consists of an inner hollow bell-shaped body lawith a' narrow through iiow Vsection between the inner valve 2 and the outer valve 1. From the section 1a on, its inner smallest diameter is steadily widened in outward direction to the maximum inner diameter equal to the outmost inner diameter of the outer Semi-spherical-shaped hollow dome 1b to obtain there a maximum of through flow area of the apertures and atl the same time a semispherically-shaped hollow dome of the outer valve, which allows a maximum through ow section through the spherical apertures 1c at a minimum of height and weight of the domed valve part 1b. A minimum of weight of the two valves 1 and 2 is of course besides large through ow sections 1c of the outmost importance to run engines according to the invention with the highest speed possible.

The outer valve lhas a tubular shaft; 1d which guides the inner valve 2. The inner valvev2 is seated on the inner hollow bell-shaped valve -portion 1a of the outer valve 1. The apertures 1c are separated by wall portions of the domed valve head 1b and each of its wall portions .1e can be situated substantially in an axial plane, see Y Figure 2. The outer valve has its seat in the cylinder head 9. vAs can be seen from Figure 2 the walls 1e between the apertures 1c may bevsituated nplanes going through the valves axis. The hollow valve stem 1d projects from the outer surface of the walls of the inner bellshaped jacket 1a and the semi-spherical-shaped outer jacket 1b respectively 1e and serves to actuate the inlet or outer valve 1. There kare no partitions, ribs, hubs, etc. in the hollow part of the bell and semi-'spherical-shaped outer valve 1. Because the inner parts of the hollow `outer valve 1 are exempt Afroin -any partitions like ribs, hubs or others, its through ow area restricting parts-- the through ow of the exhaust gasesoccurs with a minimum of pressure and velocity losses and also the weight of the outer larger valve gets smaller, 'which is-very irnportant to limit the inertia forces for their operation. The hollow part of the valve 1 4is guided in thebore 12 "of the cylinder head by theio'uter cylindrical :guide :.por-

4@ tion 11, recessed' on the outer surface of the belland semi-spherical-shap'ed portions 1a and'lin' ofk the outer valve 1. The cylindrical surface of the portion 11 is formed with singular slots 13 serving as a labyrinth sealing. The slots 13 may also contain piston rings.

Figure 2 is a section perpendicular to the axis of the cylinder head 9, showing a plan view of the outer inlet valve 1 and' of the' inner outlet` valve 2. Around the semi-spherical-shaped hollow dome 1b of the inlet valve 1 a cavity 4a, formed in the cylinder head 9 is shown. The cavity 4a opens into the outlet duct 4; The admission duct 3 for the air charge of the engine is shown in section, it is spirally formed round the outer inlet valve 1.

The wall of the apertures 1c alongside the tubular shaft 1a will be advantageously directed as much as possible parallel to the axis of the tubular shaft as seen in Figure l. The outer hollow inlet valve 1 can comprise as shown in Figure 1 an inner, outlet valve 2, receiving said outer valve, which former seats against the inner bell-shaped portion of the inlet valve and whereby the latter seats against an opening in the cylinder head 9.

Each of the two valves 1 and 2 being independently reciprocated for opening and closing them. The inlet valve 1 is opened with its bell-shaped portion 1a, its semi-spherical-shaped dome head 1b, its tubular shaft extension 1d, its spring plate 6 which is rigidly connected with the valve element 1d. The spiral spring 8 serves the purpose to close the inlet valve 1. It rests on a fixed part of the engine for instance on the cylinder head 9. The inner outlet valve 2 is closed with the spiral spring 7, which exerts its pressure via the spring plate 5 upon the stem of the outlet valve 2. The spiral spring 7 rests on a plate 21, which is held by the cylinder head 9 through bolts 20.

According to Figure 1a the closing device for the inner valve 2 can also be made up of a hairpin torsion spring 7a and a yoke Sa. The hairpin spring la can be made of ytwo separated parts as indicated in Figure la.

The inner ends of the spring 7a are xed in a plate attached to the cylinder head 9 and its outer ends are pressed downwards by the two openends of the yoke 5a. The yoke 5a is tixed by some known means to the stem of the valve 2. With a hairpin torsion spring 7a a larger lift of the inner valve can be obtained without overstressing it. With a hairpin torsion spring '7a the natural vibrations occur further at a higher frequency or speed of the engine than with an ordinary spiral spring 7 as seen in Figure l. For closing the inner valve 2 still a spiral spring 8a can be used. yIt presses against the spring plate 67a to close the outer valve 1 via its tubular valve stern 1d as seen in Figure la and l. The spiral spring 8a can rest on the cylinder head'9 itself, inside the plate, which holds the inner ends of the hairpin torsion springs 7a as also shown in Figure la.

The cavity 4ain the cylinder head of the duct 4 surrounding the semi-spherical-shaped domed head 12 of the outer valve 1 can be so arranged as seen in Figure 2 relative Lto the apertures 1c, that the through flowing pressure medium is divided in two streams, each flowing around the semi-spherical head 1b in opposed circular direction and meeting at the entrance into the common exhaust duct 4.

As also shown in'Figure 2 the semi-spherical-shaped dome 1b, 1e of the outer valve 1 is formed with three spherical triangular apertures 1c, which open into the cavity 4a and the duct 4 through which the exhaust gas controlled by the inner valve 2 vis led to the outside for example. The apertures 1c are sub-divided by means of relatively thin, circular shaped wall portions 1b and 1e, accurately machined out of the hollow outer valve body. With only three apertures 1c, one gets a maximum of ythrough iiow 'area through these apertures 1c. Only three walls l1c do not limit and ydisturb'th'e through flow Aof the gases -too muhV and with "su'ch 'a structure the valve would still 'be kept straight and in line during'the engine operation.

Figures 3 and 4 show another embodiment of 'the belland semi-spherical-shaped outer valve, namely an alternative design of the apertures 1c. Those apertures 1c are likewise sub-divided by wall portions y1e of the semispherical-shaped hollow dome 1b of the outer valve 1 as shown in Figure 4. In this case such wall portions 1e of the semi-spherical-shaped dome 1b of the valve 1 extend at an oblique angle from the outer circumference of the domed valve head 1b towards its axis. The purpose of this shape is to make possible a giving way of the valve jacket la with respect to the tubular valve stem Id thereon, when these subdivisional means are heated up by the through owing hot exhaust gases which causes expansion and elongation thereof; thus preventing a dangerous rise of mechanical stresses at heat expansion of the division walls 1e in the outer valve body.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacricing its material advantages, the forms hereinbefore described and illustrated in the drawings being merely preferred embodiments thereof.

I claim:

1. An internal combustion engine of the type comprising piston cylinders, in each cylinder an inner outlet mushroom valve having a stern for timed reciprocation thereof and a hollow outer inlet valve forming a seat for said outlet valve and having a tubular extension also for timed reciprocation thereof, a common axis for both said valves, said tubular extension surrounding and guiding said stem of the inner outlet valve, said outer inlet valve being seated against an opening in the cylinder head, and both said valves controlling, respectively, the ow of the exhaust gas and the inlet of the air charge from and to said cylinder, said outer valve being formed with a lower bell-shaped circular wall portion and an upper arcuate wall portion, said upper arcuate wall portion forming a vaulted head above said lower portion, inner and outer surfaces of said head, through-How openings around said tubular extension in the wall of said head for the exhaust gas controlled by said inner valve, said lower wall portion diverging towards its uppermost area, and forming there a maximal through-flow area for the exhaust gas, said vaulted head forming a single vault over said uppermost area of said lower wall portion, axial sections of at least said inner surface of said vault having radii of curvature of equal size, s aid radii having center points on said common axis of the valves.

2. An internal combustion engine of the type comprising piston cylinders, in each cylinder an inner outlet mushroom valve -having a stem for timed reciprocation thereof, and a lhollow outer inlet valve forming a seat for said outlet valve and having a tubular extension also for timed reciprocation thereof, a common axis for both said valves, said tubular extension surrounding and guiding said stem of the inner outlet valve, said outer inlet valve being seated against an opening in the cylinder head, and both said valves controlling, respectively, the ilow of the exhaust gas and the inlet of the air charge from and to said cylinder, said outer valve being formed with a lower bell-shaped circular wall portion and an upper arcuate wall portion, said upper arcuate wall'portion forming a vaulted head above said lower portion, inner and outer surfaces of said head, through-how openings around said tubular extension in the wall of said head for the exhaust gas controlled by said inner valve, said lower wall portion diverging towards its uppermost area, and forming there a maximal through-flow area for the exhaust gas, said vaulted head forming a single vault over said uppermost area of said lower wall portion, axial sections of at least said inner surface ot said vault radii of curvature of equal size and radii having center points on said com mon axis of the valves, wall portions of said head separating said through-flow openings, said wall portions being arcuate as viewed axially and situated in axial planes, the outer circumferential width thereof defining said through-how openings is greater than the radial thickness thereof.

3. An internal combustion engine of the type comprising piston cylinders, in each cylinder an inner outlet mushroom valve having a stem for .timed reciprocation thereof, and a hollow outer inlet valve forming a seat for said outlet valve and having a tubular extension also for timed reciprocation thereof, a common axis for both said valves, said tubular extension surrounding and guiding said stem of the inner outlet valve, said outer inlet valve being seated against an opening in the cylinder head, and both said valves controlling, respectively, the flow of the exhaust gas and the inlet of the air charge from and to said cylinder, said outer valve being formed with a lower bell-shaped circular wall portion and an upper arcuate wall portion, said upper arcuate Wall portion forming a vaulted head above said lower portion, inner and outer surfaces of said head, though-flow openings around said tubular extension in the wall of said head for the exhaust gas controlled by said inner valve, said -lower wall portion diverging towards its uppermost area, and forming there a maximal through-flow area for the exhaust gas, said vaulted head forming a single vault over said uppermost area of said lower wall portion, axial sections of at least said inner surface of said vault having radii of curvature of equal size, said radii having center points on said common axis of the valves, wall portions of said head separating said through-flow openings, said wall portions extendingV each at oblique angles to the circumference of said lower wall portion dening said uppermost area and said axis of the valves.

4. An engine as claimed in claim 3 in which the wall portions separating said through-how openings are arcuate as viewed axially of the valve and the width thereof is greater than the radial thickness.

5. 4An internal combustion engine of the type comprising piston cylinders, in each cylinder an inner outlet mush-room valve having a stem for timed reciprocation thereof and a hollow outer inlet valve forming a seat for said outlet valve and having a tubular extension also for timed reciprocation thereof, said tubular extension surrounding and guiding said stem of the inner outlet valve, said outer inlet valve being seated against an opening in the cylinder head and both said valves controlling the flow of the exhaust gas and the inlet of the air charge from and to said cylinder, said outer valve being formed with a lower bell shaped circular wall portion and an upper arcuate wall portion, said upper arcuate wall portion forming a domed head above said lower portion, through-'flow openings around saidy tubular extension in the wall of said domed head for the exhaust gas controlled by said inner valve,isaid lower wall portion diverging towards its upper uppermost area, said domed head extending over said uppermost area of said lower wall portion, said tubular shaft extending outwardly from said domed head and said inner shaft extending free of guide means through the interiorb of the outer valve, whereby the weight of said outer valve is kept relatively small and the cross-sectional flow area within said outer valve is not interfered with by such guide means and can be made relatively large,

6. An internal combustion engine as claimed in claim 5, wherein said head comprises wall portions separating said through-flow openings and wherein said wall portions are arcuate as viewed axially and situated in axial planes and the width thereof is greater than the radial thickness thereof.

7. An internal combustion engine as claimed in claim 5 wherein said head comprises wall portions separating said through-flow openings, said wall portions as viewed thickness.

8. An internal combustion engine aszclaimed inelarnA 5 wherein said head comprises triangular4 through-flow openings, the bases of said openings being greater than their heights measured axially.

References. Cited in t'l-le Qfihs .panne UNITED STATES PATENTS Greuten e Marf-- 2-8, 19171 Van Keuren- Nov. 9, 1915 Buchy Sept-v 3;- 1940 FOREIGN PATENTS.

Greatritain."v Oct. 17,1906 

